Many thanks, knew you guys would have the answer, its my own laziness I've never got round to changing the battery, as the bike always seemed to fire up first time. 10 years, and long periods of sitting is maybe pushing it a `bit`however..

Looks like two for two recommendations on a Yuasa so I`ll pick up a TY9B-BS one this week, considering its only �60 or so from various sources by the looks of it.

So i simply swap it out and it shouldn't mess with the immobilizer? That was my biggest worry, considering the age of the existing battery. Didn't want suddenly stranded somewhere with a bricked bike...? Is there anything I should be looking out for or doing specifically? Its a simple battery swap but again, always handy to know any tips.

Out of curiosity, if the immobilizer does somehow trigger at any point is it an easy fix to reset? Got the red master key but wandered what the process actually is. Its always something that I've wondered about but one of those things I've never really bothered to investigate in much detail, but the whole thing has got me thinking.

Andy